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Author Topic:   Evidence that the Great Unconformity did not Form Before the Strata above it
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 421 of 1939 (754116)
03-24-2015 2:08 PM
Reply to: Message 418 by jar
03-24-2015 1:56 PM


Re: No failure, just up against OE incredulity
Most of that is off topic.

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 Message 418 by jar, posted 03-24-2015 1:56 PM jar has replied

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jar
Member (Idle past 394 days)
Posts: 34026
From: Texas!!
Joined: 04-20-2004


Message 422 of 1939 (754118)
03-24-2015 2:26 PM
Reply to: Message 421 by Faith
03-24-2015 2:08 PM


Re: No failure, just up against OE incredulity
Faith writes:
Most of that is off topic.
In Message 412 did you not post "And what is your model anyway? Just a bunch of suppositions looks like to me. "
When I respond to a direct question with links and evidence can it be off topic?
Now, since I responded perhaps you can provide the links to support your claim also from that same message that you have already presented the model, mechanism, method, process, procedure that can explain what is seen.
And as Percy has requested we repeat pertinent information:
quote:
As to the conventional model I began explaining it to you in Message 4, Message 122, Message 153, Message 220, Message 225, Message 322 as well as by many other posters and in many other threads like Exploring the Grand Canyon, from the bottom up. and Salt of the Earth (on salt domes and beds) and How to make sand. and explained that none of it is speculation but rather supported by all of the evidence.
The links I provide contain the full description of how to make schist or sandstone or granite or shale or limestone.
That was what you requested.

Anyone so limited that they can only spell a word one way is severely handicapped!

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Admin
Director
Posts: 12998
From: EvC Forum
Joined: 06-14-2002
Member Rating: 2.3


Message 423 of 1939 (754119)
03-24-2015 2:26 PM
Reply to: Message 420 by Faith
03-24-2015 2:06 PM


Faith writes:
If I'm getting you, yes, I'm saying that the presently "exposed cliff face" was eroded after being exposed.
But what you've just said, that the cliff face was eroded after being exposed, isn't what people are taking issue with. If that's all you were really saying then everyone would agree with you because every exposed surface is always being eroded, it only being a matter of degree.
We're trying to understand what you think happened to transform this from a couple hundred years ago:
Into this today (ignore the blue outlined area):
There are two options:
  1. The part of the boundary exposed a couple hundred years ago happened to be straight. In the couple hundred years since, the cliff face has eroded back a number of feet, enough to expose a different part of the same boundary, one that happens to be much more uneven.
  2. The cliff face we see today is basically the same one as a couple hundred years ago. In the couple hundred years since, severe weathering has caused the straight boundary to deform and become very uneven
Or is it something else. Please let us know.
But as I was looking at your version of the picture you marked with the straight line I began to doubt that edge had identified the lower strata correctly anyway. Some of it looks like it belongs in the eroded zone above it.
But even if the yellow line were redrawn as you would like, it would still be uneven, right?
PS: Edge - Are you deleting photos from PhotoBucket that you've linked to from your messages? And me, too?

--Percy
EvC Forum Director

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 424 of 1939 (754120)
03-24-2015 2:37 PM
Reply to: Message 423 by Admin
03-24-2015 2:26 PM


Faith writes:
If I'm getting you, yes, I'm saying that the presently "exposed cliff face" was eroded after being exposed.
But what you've just said, that the cliff face was eroded after being exposed, isn't what people are taking issue with. If that's all you were really saying then everyone would agree with you because every exposed surface is always being eroded, it only being a matter of degree.
We're trying to understand what you think happened to transform this from a couple hundred years ago:
...Into this today (ignore the blue outlined area):
There are two options:
1.The part of the boundary exposed a couple hundred years ago happened to be straight. In the couple hundred years since, the cliff face has eroded back a number of feet, enough to expose a different part of the same boundary, one that happens to be much more uneven.
2.The cliff face we see today is basically the same one as a couple hundred years ago. In the couple hundred years since, severe weathering has caused the straight boundary to deform and become very uneven
Or is it something else. Please let us know.
Hard to follow so many different options. But I'll just try to state more clearly what I had in mind.
The drawing I posted I believe represents accurately what was actually there: Distinct upper horizontal and lower vertical sections with a straight contact line.
To explain edge's photo of the irregular contact line I figure the upper section was partly eroded away from the lower, could be a matter of inches rather than feet but I'm not sure of the scale, exposihg the upper surface of the lower strata to weathering which has made it irregular over the last couple hundred years.
ABE: So, rereading, I think your option 2 is closest but it needs the exposure of the upper surface of the cliff face brought about by erosion of the upper section.
Edited by Faith, : No reason given.
Edited by Faith, : No reason given.

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 425 of 1939 (754121)
03-24-2015 2:42 PM
Reply to: Message 423 by Admin
03-24-2015 2:26 PM


But even if the yellow line were redrawn as you would like, it would still be uneven, right?
Somewhat but not a lot.

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jar
Member (Idle past 394 days)
Posts: 34026
From: Texas!!
Joined: 04-20-2004


Message 426 of 1939 (754122)
03-24-2015 2:51 PM
Reply to: Message 390 by herebedragons
03-24-2015 10:21 AM


weathering the ages
Something I was thinking about...
there is no evidence that land plants had colonized the land even as late as the Cambrian. Of course, that could be an artifact of the erosion that wiped that surface clean, but if that is true, then none of the surface of the GU would have been secured by plant roots and would have suffered extreme erosion, at a far greater rate than we observe today.
HBD
Lately I've come across several articles along those lines. Here is a letter that was published in Nature a couple years ago that speculates that the Great Unconformity points to one possible trigger mechanism for the Cambrian Explosion.

Anyone so limited that they can only spell a word one way is severely handicapped!

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herebedragons
Member (Idle past 858 days)
Posts: 1517
From: Michigan
Joined: 11-22-2009


(1)
Message 427 of 1939 (754126)
03-24-2015 3:03 PM
Reply to: Message 396 by Faith
03-24-2015 10:52 AM


Re: G U too flat to be eroded: images
Again, as usual, there is some kind of huge disconnect in this discussion that makes no sense to me.
After reading today's posts, I again get the impression that you don't understand what we mean by an unconformity. I realize that you think that unconformities form in a different way than we do, but it would be really helpful if we were all talking about the same thing. So at the risk of being patronizing I thought I would put up this image of an nonconformity for you viewing pleasure.
The "thing" we are referring to as the "unconformity" or the "surface of the unconformity" is the surface in figure C that has grass growing on it. That surface is the unconformity. It is not exposed to erosion after the upper sediments are laid down.
Figure D would be a depiction of the face, or cross section, that is exposed to erosion and what is visible to us. The thin line is the unconformity (in cross section) but the surface that has been overlain with horizontal sediment (in Fig C) is THE unconformity.
If I am wrong and you understand this, I apologize, but why would the surface of the unconformity that is buried many feet back from the exposed face be subject to erosion?
If you have some other understanding of an unconformity, what is it??
HBD

Whoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca
"Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem.
Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.

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Replies to this message:
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herebedragons
Member (Idle past 858 days)
Posts: 1517
From: Michigan
Joined: 11-22-2009


Message 428 of 1939 (754131)
03-24-2015 3:15 PM
Reply to: Message 401 by Faith
03-24-2015 11:16 AM


Just for the record, if I were thinking in terms of half a billion years I would expect the Grand Canyon long since to have dissolved into a pile of dust.
But you don't think erosion can reduce a landscape to dust even in a hundred billion years, so why would you expect the GC to be "reduced to dust."
And besides, the GC has been reduced to dust.
HBD

Whoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca
"Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem.
Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.

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 Message 401 by Faith, posted 03-24-2015 11:16 AM Faith has replied

Replies to this message:
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Admin
Director
Posts: 12998
From: EvC Forum
Joined: 06-14-2002
Member Rating: 2.3


Message 429 of 1939 (754134)
03-24-2015 3:20 PM
Reply to: Message 424 by Faith
03-24-2015 2:37 PM


Faith writes:
The drawing I posted I believe represents accurately what was actually there: Distinct upper horizontal and lower vertical sections with a straight contact line.
Is this the drawing you mean:
The contact point between the upper and lower layers appears very similar to Edge's photo, fairly straight to the right, fairly uneven to left:
The diagram was drawn from a different angle than the photo, accounting for some of what appear to be differences but probably aren't. Here's an image with some people in it to give you some perspective:
To explain edge's photo of the irregular contact line...
Both the diagram and Edge's photo show irregular contact lines, so you need to explain both.
...I figure the upper section was partly eroded away from the lower, could be a matter of inches rather than feet but I'm not sure of the scale, exposing the upper surface of the lower strata to weathering which has made it irregular over the last couple hundred years.
ABE: So, rereading, I think your option 2 is closest but it needs the exposure of the upper surface of the cliff face brought about by erosion of the upper section.
I'm still not sure what you're saying. Do you mean that the lower layer at the boundary was eroded more than the upper layer, and that the boundary is still straight, it's just that there's now the appearance of being uneven? Here's the image without the yellow line - it might help because it gives a better idea of which layers stick out from the cliff face more than others:
Edited by Admin, : Clarify last para.

--Percy
EvC Forum Director

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 430 of 1939 (754137)
03-24-2015 3:20 PM
Reply to: Message 423 by Admin
03-24-2015 2:26 PM


I spent a little time on that photo and came up with the following: the only part of the lower section that remains above the straight line you drew is the small piece to the right of the dike. My own squiggly yellow line falls below yours. I also outlined in lt. blue the zone that looks more like erosion than like either of the strata sections.
'
Edited by Admin, : Remove the URL from the image - it makes zooming the image very inconvenient.

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 431 of 1939 (754139)
03-24-2015 3:25 PM
Reply to: Message 428 by herebedragons
03-24-2015 3:15 PM


But you don't think erosion can reduce a landscape to dust even in a hundred billion years, so why would you expect the GC to be "reduced to dust."
Not flat level dust.
And besides, the GC has been reduced to dust.
That's a lot of solid organized dust if so.

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dwise1
Member
Posts: 5930
Joined: 05-02-2006
Member Rating: 5.8


Message 432 of 1939 (754143)
03-24-2015 3:45 PM
Reply to: Message 416 by Faith
03-24-2015 1:20 PM


This is an ordeal with a malfunctioning space bar. Must have splashed something on it.
Or there might be something lodged underneath it. That happened to me once with the shift key I normally use to type my password when I start my computer. After the first flash of panic, I noticed that the key wasn't travelling down fully. After I gave it a blast of canned air, it worked fine.
Could be a bread crumb or a seed or a clump of lint. It can make even more of a difference on a laptop whose keys have very little travel. If you have canned air, try that. If not, then you could your own breath, but that can be difficult to keep dry. Or you could tilt the keyboard in various directions and either shake or tap (ie, like somebody menacingly slapping a club into the palm of the other hand, though much more gently).

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 Message 416 by Faith, posted 03-24-2015 1:20 PM Faith has replied

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 433 of 1939 (754145)
03-24-2015 3:47 PM
Reply to: Message 427 by herebedragons
03-24-2015 3:03 PM


Re: G U too flat to be eroded: images
Perhaps my basic rejection of the idea of how such an unconformity develops makes it too hard for me to think in such terms at all. Certainly I think I get that it's the horizontal surface that cuts across the folded strata but I reject the whole idea of the order of things presented in your diagram. Maybe that is causing all the miscommunication? Perhaps it would help if you applied your diagram to Siccar Point with a view to explaining where we are misunderstanding each other.

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Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 434 of 1939 (754146)
03-24-2015 4:02 PM
Reply to: Message 432 by dwise1
03-24-2015 3:45 PM


Thanks. Could be that I guess. I've blown on it but no change. I do have canned air but never used it. They say to remove a certain tab but the likely candidate doesn't want to come off.

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New Cat's Eye
Inactive Member


Message 435 of 1939 (754149)
03-24-2015 4:15 PM
Reply to: Message 433 by Faith
03-24-2015 3:47 PM


Re: G U too flat to be eroded: images
Perhaps my basic rejection of the idea of how such an unconformity develops makes it too hard for me to think in such terms at all.
How are you going to provide evidence against something if you can't even think it its terms?

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